Help:Reading

Because the vast majority of the ArchWiki contains indications that may need clarification for users new to Arch Linux (or GNU/Linux in general), this rundown of basic procedures was written both to avoid confusion in the assimilation of the articles and to deter repetition in the content itself.

Organization

Most articles on the ArchWiki do not attempt to provide a holistic introduction to a single topic; they are instead written in adherence to the DRY principle, under the assumption that the user will seek out and read any supporting material that they do not yet understand. Where possible, such supporting material is indicated in the article via special formatting, see #Formatting.

Because of this organization, it may be necessary to examine several related sources in order to fully understand an ArchWiki article. In particular, users who are new to Arch (or GNU/Linux in general) should expect to end up reading a great number of articles even when solving simple problems. It is especially important to study the supporting material before seeking additional help from other users.

Regular user or root

The numeral or hash sign (#) indicates that the command needs to be run as root, whereas the dollar sign ($) shows that the command should be run as a regular user.

Note: The commands prefixed with # are intended to be executed from a root shell, which can for example be easily accessed with sudo -i. Running sudo command from an unprivileged shell instead of command from a root shell will also work in most cases, with some notable exceptions such as redirection and command substitution, which strictly require a root shell. See also sudo.

A notable exception to watch out for:

# This alias makes ls colorize the listing
alias ls='ls --color=auto'

In this example, the context surrounding the numeral sign communicates that this is not to be run as a command; it should be edited into a file instead. So in this case, the numeral sign denotes a comment. A comment can be explanatory text that will not be interpreted by the associated program. Bash scripts denotation for comments happens to coincide with the root PS1.

After further examination, "give away" signs include the uppercase character following the # sign. Usually, Unix commands are not written this way and most of the time they are short abbreviations instead of full-blown English words (e.g., Copy becomes cp).

Regardless, most articles make this easy to discern by notifying the reader:

Append to ~/path/to/file:

# This alias makes ls colorize the listing
alias ls='ls --color=auto

Append, add, create, edit

When prompted to append to, add to, create, or edit one or more files, it is implied that you should use one of the following methods.

To create or modify multiline files it is suggested to use a text editor. For example, using nano the command to edit the file /etc/bash.bashrc is:

# nano /etc/bash.bashrc

To create or overwrite a file from a string it may be simpler to use output redirection. The following example creates or overwrites the contents of the file /etc/hostname with the text myhostname.

# echo myhostname > /etc/hostname

Output redirection can also be used to append a string to a file. The following example appends the text [custom-repo] to the file /etc/pacman.conf.

Make executable

After creating a file, if it is meant to be run as a script (whether manually or called by another program) it needs to be set as executable, for example with:

$ chmod +x script

See chmod. Some applications such as file managers may provide graphical interfaces to do the same.

Source

Some applications, notably command-line shells, use scripts for their configuration: after modifying them, they must be sourced in order for the changes to be applied. In the case of bash, for example, this is done by running (you can also replace source with .):

$ source ~/.bashrc

When the wiki will suggest to modify such a configuration script, it will not explicitly remind you to source the file, and only in some cases it will point you to this section with a reminder link.

Installation of packages

When an article invites you to install some packages in the conventional way, it will not indicate the detailed instructions to do so, instead it will simply mention the names of the packages to be installed.

Note: Frequently, the install or installed links are used to point to this article section. However, JavaScript has to be enabled for these links to work.

The subsections below give an overview of the generic installation procedures depending on the package type.

The start link will lead you to the systemd article, which contains all the detailed explanations to deal with systemd units in Arch Linux proficiently.

Note: The start, enable, stop, restart... links are redirects to specific sections, which work only if JavaScript is enabled.

System-wide versus user-specific configuration

It is important to remember that there are two different kinds of configurations on a GNU/Linux system. System-wide configuration affects all users. Since system-wide settings are generally located in the /etc directory, root privileges are required in order to alter them. For example, to apply a Bash setting that affects all users, /etc/bash.bashrc should be modified.

User-specific configuration affects only a single user. Dotfiles are used for user-specific configuration. For example, the file ~/.bashrc is the user-specific configuration file. The idea is that each user can define their own settings, such as aliases, functions and other interactive features like the prompt, without affecting other users' preferences.

Note:~/ and $HOME are shortcuts for the user's home directory, usually /home/username/.

Pseudo-variables in code examples

Some code blocks may contain so-called pseudo-variables, which, as the name says, are not actual variables used in the code. Instead they are generic placeholders and have to be manually replaced with system-specific configuration items before the code may be run or parsed. Common shells such as bash and zsh provide tab-completion to auto-complete parameters for common commands such as systemctl.

Enable the dhcpcd@interface_name.service for the network interface identified from the output of the ip link command.

In this case interface_name is used as a pseudo-variable placeholder in a systemd template unit. All systemd template units, identifiable by the @ sign, require a system-specific configuration item as argument. See Systemd#Using units.

The command dd if=data_source of=/dev/sdX bs=sector_size count=sector_number seek=partitions_start_sector can be run as root to wipe a partition with the specific parameters.

Reason: Mention other examples, ideally from other device categories (e.g. storage), with links to background articles. The examples are meant to avoid duplicating existing explanations in other articles. (Discuss in Help talk:Reading#)

In case of file examples, pasting pseudo-variables in real configuration files might break the programs that use them.

Ellipses

In most cases ellipses (...) are not part of the actual file content or code output, and instead represent omitted or optional text that is not relevant for the discussed subject.